Internal-combustion engine



may 20, H924. 3,494,450

' v C. W., E. CLARKE INTERNAL coMBU'sTIoN ENGINE Filed Aux. 13 1917 UNET@ CHARLS W. E. CLARKE, OF BRO'DKLINE, .MASSACHUSETTS INTERNAL-COMBUSTION ENGINE.

Application led August 13, 1917. Serial No. 185,819.

To all @cham t may conce/m.'

Bel 1t known that l, CHARLES W. E. CLAiuin, a citizen of the United States, re-

siding atliroolrline, in the county of Nor-` folk and State of Massachusetts, have in- .vented certain Improvements in Internal- Combustion Engines, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

rlhis invention relates to internal combustion engines and is particularly concerned with the type of engine of this character which is provided with a plurality of inlet and outlet valves for each cylinder. Engines of this type have been used to only a relatively limited extent heretofore but are rapidly going intol use particularly for automobile and aeroplane service. The present invention has for its chief object to increase the flexibility of control of engines of this type and also to improve the economypf these engines.

The various features of the invention will be readily understood from the following description, reference being made to othe accompanying drawings, in which- Figure 1. is a plan View of those parts of an internal combustion engine necessary tov type, indicated at 2 and 3, respectively, and

also with two outlet valves, one of which is indicated at 4f in Fig. 3. An inlet manifold 5 leads from the carbureter 6 to theinlet valves ofthe cylinders and an exhaust manifold 7 conducts the burnt gases away from the outlet valves.`

The inlet valves 2 and 3 of each cylinder are operated from a cam shaft 8 carrying a series of cams, two of which are indicated wat 9 and 10, Fig. 2, and which co-operate with suitable valve stems 11 to lift the valves 2 and 3 off their seats at the proper timesin the cycle of operation of the engine to admit fuel to the cylinder. Springs indicated at 12 hold the valve stems in contact with the cams 9 and v1() and tend to seat the valves. The outlet valves are operated in a similar manner by a cam shaft 141 lying parallel with the shaft Sand on the opposite side of the, main crank shaft 15 from the shaft 8. ln order to rotate the cam shaftsA Sand-14, they have secured to their forward ends pinions 16 and 1i?,l respectively, which mesh with a barrel gear 18 mounted fast on the main shaft 15. .a

In the usual arrangement'in engines having four valves per cylinder, as in the construction shown, the two inlet valvesrv open and close simultaneously and the two outlet valves also open and close simultaneously. The valve movement is relatively short so that often the entire port area. is not available for the iiow of gases into or out of the engine cylinder. In the present arrangement the operating mechanism for the valves is so arrangedthat the operator can vary the number of valves of. each cylinder in operation at any time and 'can also adjust the length of stroke of the valves. For this purpose the cam 9 which operates the valve 2 is provided with a relatively long cylindrical portion a in which the elements ofv the cam face all lie parallel to the axis of the cam shaft 8; another portion b extending forward from the part a and havin the elements of the rise 'of the cam, that 1s the part of the camthat produces the valvelifting movement, inclined with relation to the axis of the shaft 8; and another part c at the end of the part' b in which the cam face elements all extend parallel to the shaft 8. The cam l() which operates the valve 3 is provided with similar camy faces a, b and c, but this cam differs from the cam 9 in that the part a is very short, about equal in length to the part c of the cam 9, while the part c ofthe cam 10 is about equal in length to the part a of the cam 9, the inclined parts b of both cams being substantiallyequal in lengthf, This cam shaft is adjustable longitudinally of its axis so that any part a, b or c of either cam 9 or 10 may be made to operate its respective valve 2 or 3.

When the `shaft 8 is in the positionin est part c of the cam 10. If this shaft were,

- 3 would receive a shorter valve-openingl movement as this adjustment proceeded toward the right,'while the valve 2 would still f remain inoperative. rIhis adjustment would reduce the power produced by the engine since the shorter valve movement would afj ford less area for the flow` of gas into the cylinder thanwould a longer stroke. If, on the other hand, the shaft 8 were moved to the left, as the parts appear in Fig. 2, then the valve 3 would still continue to open its maximum distance at each rotation of the `cam 10, while the valve 2 would be brought -into' operation due to the fact that the inclined part of the cam 9 would be moved into co-operative relationship to the stem of this valve. If this adjustment of the shaft 8 toward the left were made sufficientto bring the art c of the cam 9 under the stem of the va ve 2, this valve then would be given its maximum length of stroke while the valve 3 also would continue to make its maximum opening movement at each rotation of the shaft 8. rIhe exhaust valves are similarly operated.

For the purpose of effecting this adjustment of the shafts 8 and 14 they are mounted to slide in their hearingsv in the base of the engine and an adjusting mechanism is provided which comprises a yoke 20 mounted to rock on a. rock shaft 2l and having pins or rolls that enter vthe grooves or collars fixed, respectively, on the shafts 8 and 14, one of which collars is indicated at 22 in Fig. 2. A lever 23 fastened to the rock shaft 21 is connected by a link 24 to a hand operated lever,.25 which is provided with a spring pressed latch designed to( engage the teeth of a segment 26 along which it swings when the lever is rocked. This is a well known adjusting lever construction, the latch serving to maintain the lever in its adjusted position. It is obvious from an inspection of Fig. 2 that as the lever 25 is swung forward or backward, it. will move the shafts 8 and '14 forward or backward in 'their bearings and thus adjust the cams carried by these shafts relatively to the valve stems which they operate, with the results above described.

The supply of fuel to the inlet valves may be varied by the throttle 27, Fig. 1 in the usual manner and the adjustment of the throttle may 'be either independent of or connected with the adjusting mechanism for the valve operating means. In the arrangement shown a rod 28, connected at one end to the throttle 27 and at its opposite end .adjustably fastened by the connector 29 tothe link 24, enables the operator to adjust the throttle simultaneous y acca-icc with the adjustment of the valve operating mechanisms. y

It Iwill readily be appreciated that this arrangement affords an exceedingly flexible control for the engine and reduces the wear and tear on the valve mechanism at low speeds while providing the very large valve opening desirable in order to operate t-he engine at high speeds or whenever its maximum power is required. It is obvious that the valve opening is multiplied very substantially between the adjustment which permits theminimum flow of fuel toeach cylinder and that which permits a maximum flow of fuel. The engine shown operates as a two/valve per cylinder engine while producing a relatively small percentage of its maximum power, and as a four valve per cylinder engine while producing a high percentage of its maximum power.

It will also be understood that the disclosure herein made is intended rather by way of explanation than limitation and that the invention may be embodied in many forms while still retaining its essential features and characteristics.

What is claimed as new is:

1. In an internal combustion engine having a pluralitty of valves controlling the admission of uel to each cylinder, `means for supplying fuel to said valves, operatin mechanism for said valves constructed an arranged. for adjustment while the engine is in operation to vary the length of stroke of the valves, andmanual controlling means common to said fuel supply and said operating mechanism.

2. In an internal combustion engine having a plurality of inlet valveslfor each cylinder, operatin mechanism for said valves constructed and arranged normally to'operate one valve only of each cylinder but arranged for adjustment` to enable the operator to increase at will the length of stroke of said valves and thereafter to bring another valve into operation in each cylinder when the first valve has substantially reached its maximum stroke.

3. In an internal combustion engine having a plurality of inlet valves Ifor each cylinder, operating mechanism for said valves constructed and arranged for adjustment whlle the engine is in operation to va the number of valves in operation in eadlli cylinder and to adjust the length of stroke of said valves, and additional means arranged to be operated simultaneously with said adjustment to vary the supply of fuel to said inlet valves.

4. In an internal combustion engine havinga plurality of inlet valves for each cylinder, operating mechanism for said valves constructed and arranged lfor adjustment while the engine is in operation to vary the Meme@ stroke of the valves between a, xed minimum and a ixed maximum, said operating mechanism being operative to vary the stroke of one velvewithout changing the 5 operation of the other valve.

5. In an internal combustion engine having a plurality of inlet valves for each cylinder, operating mechanism for seid Valves constructed and arranged for adjustment l0 while the engine is in operation to vary 'the number of said valves in opeetion in each cylinder, said mechanism including s hand operated. device for effecting said adjustment, and means connected with said device and arranged to be ogereted thereb Simultaneously Wlth said adjustment to e feet a predetermined change in the supply of fuel to said inlet vulves.

1n testimony whereof l have signed my name to this specification.

CHARLES W. E. CLARKE. 

